Semiconductor storage device
A semiconductor storage device includes a third semiconductor layer and a fourth semiconductor layer. The third semiconductor layer has a first width; the third semiconductor layer and a first insulating layer are disposed apart with a first distance; the third semiconductor layer and a second insulating layer are disposed apart with a second distance; the fourth semiconductor layer has a second width; the fourth semiconductor layer and the first insulating layer are disposed apart with a third distance; and the fourth semiconductor layer and the second insulating layer are disposed apart with a fourth distance. A shorter one of the first distance and the second distance is shorter than a shorter one of the third distance and the fourth distance, and the first width is larger than the second width.
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This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2021-049127, filed Mar. 23, 2021, the entire contents of which are incorporated herein by reference.
FIELDEmbodiments described herein relate generally to a semiconductor storage device.
BACKGROUNDA semiconductor storage device includes a substrate, plural gate electrodes stacked in a direction intersecting a front surface of the substrate, semiconductor layers next to the plural gate electrodes, and gate insulating layers interposed between the gate electrodes and the semiconductor layers. The gate insulating layers each include data-storable memory portions such as an insulative charge storage portion of silicon nitride (Si3N4), for example, and a conductive charge storage portion such as a floating gate.
Embodiments provide a semiconductor storage device that enables higher integration.
In general, according to one embodiment, a semiconductor storage device includes: a first conductive layer extending in a first direction; a second conductive layer extending in the first direction and disposed apart from the first conductive layer in a second direction intersecting the first direction; a third conductive layer extending in the first direction and disposed apart from the first conductive layer and the second conductive layer in the second direction; a plurality of first semiconductor layers interposed between the first conductive layer and the second conductive layer, each of the plurality of first semiconductor layers including regions adjacent the first conductive layer and the second conductive layer, respectively; a plurality of first memory cells interposed between the first conductive layer and the plurality of first semiconductor layers; a plurality of second memory cells interposed between the second conductive layer and the plurality of first semiconductor layers; a plurality of second semiconductor layers interposed between the second conductive layer and the third conductive layer, each of the plurality of second semiconductor layers including regions adjacent the second conductive layer and the third conductive layer, respectively; a plurality of third memory cells interposed between the second conductive layer and the plurality of second semiconductor layers; a plurality of fourth memory cells interposed between the third conductive layer and the plurality of second semiconductor layers; a first insulating layer interposed between the first conductive layer and the second conductive layer, the first insulating layer being wider than the plurality of first semiconductor layers and the plurality of second semiconductor layers in the second direction; and a second insulating layer interposed between the second conductive layer and the third conductive layer, the second insulating layer being wider than the first semiconductor layers and the second semiconductor layers in the second direction. A third semiconductor layer and a fourth semiconductor layer from among the plurality of first semiconductor layers are provided as follows: the third semiconductor layer has a first width in the first direction; the third semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a first distance; the third semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with a second distance; the fourth semiconductor layer has a second width in the first direction; the fourth semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a third distance; and the fourth semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with a fourth distance. A shorter one of the first distance and the second distance is shorter than a shorter one of the third distance and the fourth distance, and the first width is larger than the second width.
Hereinafter, a semiconductor storage device according to an embodiment will be described in detail with reference to the accompanying drawings. The following embodiment is provided for exemplifying purposes only and is not intended to limit the disclosure. The drawings below are schematic diagrams from which some components, for example, may be omitted for convenience of description. In some cases, common components in plural embodiments are denoted with identical reference signs and will not be repeatedly elaborated.
In this specification, a “semiconductor storage device” may mean a memory die or may mean a memory system including a control die, such as a memory chip, a memory card, and a solid state drive (SSD). Moreover, the “semiconductor storage device” may mean a structure including a host computer, examples of which include a smartphone, a tablet device, and a personal computer.
In this specification, when a first component is “electrically connected” to a second component, the first component may be connected to the second component directly or with a component such as wiring, a semiconductor member or a transistor. For example, when three transistors are connected in series, a first transistor is “electrically connected” to a third transistor even when a second transistor is off.
In this specification, when a first component is “interposed between” a second component and a third component, the first component, the second component, and the third component may be connected in series, and at the same time, the second component may be connected to the third component with the first component.
In this specification, a predetermined direction parallel to an upper surface of a substrate is referred to as an “X direction”, a direction parallel to the upper surface of the substrate and orthogonal to the X direction is referred to as a “Y direction”, and a direction orthogonal to the upper surface of the substrate is referred to as a “Z direction”.
In this specification, a direction along a predetermined plane may be referred to as a “first direction”, a direction along the predetermined plane and intersecting the first direction may be referred to as a “second direction”, and a direction intersecting the predetermined plane may be referred to as a “third direction”. Each of the first direction, the second direction, and the third direction may or may not correspond to one of the X direction, the Y direction, and the Z direction.
In this specification, terms such as “upper” and “lower” are used with the substrate as a reference. For example, a direction away from the substrate along the Z direction is referred to as “upper”, and a direction toward the substrate along the Z direction is referred to as “lower”. A lower surface and a lower end of a component means a surface and an end of this component on the substrate side, and an upper surface and an upper end of the component means a surface and an end of the component on a side opposite the substrate side. A surface of the component intersecting the X direction or the Y direction is referred to as a “side surface”, for example.
First EmbodimentConfiguration
The semiconductor storage device according to this embodiment includes a memory cell array MCA and a controller CU to control the memory cell array MCA.
The memory cell array MCA includes plural memory units MU. Each of the plural memory units MU includes two memory strings MSa and MSb electrically independent. One end of each of the memory strings MSa and MSb is connected to a drain-side select transistor STD and connected to a common bit line BL with the drain-side select transistor STD. The other end of each of the memory strings MSa and MSb is connected to a source-side select transistor STS and connected to a common source line SL with the source-side select transistor STS.
Each of the memory strings MSa and MSb includes plural memory cells MC connected in series. Each of the memory cells MC is a field-effect transistor including a semiconductor layer, a gate insulating layer, and a gate electrode. The semiconductor layer functions as a channel region. The gate insulating layer includes a charge storage portion where data is storable. A threshold voltage of the memory cell MC changes in accordance with a charge amount in the charge storage portion. The gate electrode is part of a word line WL.
Each of the select transistors STD and STS is a field-effect transistor including a semiconductor layer, a gate insulating layer, and a gate electrode. The semiconductor layer functions as a channel region. The gate electrode of the drain-side select transistor STD is part of a drain-side select gate line SGD. The gate electrode of the source-side select transistor STS is part of a source-side select gate line SGS.
The controller CU generates a voltage required for read, write, and erase operations, for example, and supplies the voltage to the bit line BL, the source line SL, the word lines WL, and the select gate lines SGD and SGS. The controller CU may include, for example, plural transistors and wiring disposed on the same substrate as the memory cell array MCA or may include plural transistors and wiring disposed on a substrate different from the substrate of the memory cell array MCA.
The semiconductor storage device according to this embodiment includes a semiconductor substrate 100. In the illustrated example, on the semiconductor substrate 100, four memory cell array regions RMCA are disposed in the X direction and the Y direction. Each of the memory cell array regions RMCA includes plural memory blocks BLK disposed in the Y direction. Each of the memory blocks BLK extends in the X direction.
The semiconductor substrate 100 is, for example, a semiconductor substrate of a material such as monocrystal silicon (Si). The semiconductor substrate 100 has, for example, a dual-well configuration including an n-type impurity layer on an upper surface of the semiconductor substrate and a p-type impurity layer inside the n-type impurity layer. It is noted that components such as transistors and wiring that constitute at least part of the controller CU (see
As illustrated in
Each of the stacked body structures LS (see
Each of the trench structures AT (see
Each of the memory hole regions RMH includes plural semiconductor layers 120 in the X direction. As illustrated in
The ladder regions RLD may or may not include insulating layers STH of silicon oxide (SiO2), for example. As illustrated in
It is noted that as illustrated in
As illustrated in
The semiconductor layer 115 (see
The semiconductor layer 116 is disposed below the semiconductor layer 115. The semiconductor layer 116 extends in the X direction. The semiconductor layer 116 includes polycrystal silicon (Si), for example. The semiconductor layer 116 functions as part of the source line SL (see
In the following description, when two of the stacked body structures LS adjacent in the Y direction are focused on, the plural conductive layers 110 of one of the stacked body structures LS will be occasionally referred to as conductive layers 110a (see
The semiconductor layers 120 extend in the Z direction (see
A semiconductor layer 121 (see
In the illustrated example, a lower end of the semiconductor layer 120 is connected to the semiconductor layer 116.
The gate insulating layer 130 (see
The tunnel insulating layer 131 includes, for example, an insulating layer of silicon oxide (SiO2), silicon oxynitride (SiON) or other materials. As illustrated in
The charge storage layer 132 is, for example, a floating gate of polycrystal silicon containing an N-type impurity such as phosphorus (P) or a P-type impurity such as boron (B). It is noted that the charge storage layer 132 may be an insulative charge storage portion containing silicon nitride (SiN), for example.
In the following description, as illustrated in
As illustrated in
The insulating layer 134 is, for example, a stacked film of a material such as silicon oxide (SiO2) or of titanium nitride (TiN) and silicon oxide (SiO2). As illustrated in
The high dielectric layer 135 includes, for example, an insulative material of a relatively high relative dielectric constant such as hafnium silicate (HfSiO). As illustrated in
The insulating layer 136 includes, for example, an insulating layer of a material such as silicon oxide (SiO2). As illustrated in
The insulating layers STH (see
Widths of Semiconductor Layers 120
Next, widths of the plural semiconductor layers 120 in the X direction will be described with reference to
As illustrated in
This aspect will be described in more detail below. In the following description, one of the conductive layers 110 extending in the X direction will be referred to as conductive layer 110_a1. Another of the conductive layers 110 that is separate from the conductive layer 110_a1 in the Y direction and extends in the X direction will be referred to as conductive layer 110_b2. Another of the conductive layers 110 that is separate from the conductive layer 110_a1 and the conductive layer 110_b2 in the Y direction and extends in the X direction will be referred to as conductive layer 110_a3. The plural semiconductor layers 120 interposed between the conductive layer 110_a1 and the conductive layer 110_b2, disposed in the X direction, and next to the conductive layer 110_a1 and the conductive layer 110_b2 will be referred to as plural semiconductor layers 120_1. The plural semiconductor layers 120 interposed between the conductive layer 110_b2 and the conductive layer 110_a3, disposed in the X direction, and next to the conductive layer 110_b2 and the conductive layer 110_a3 will be referred to as plural semiconductor layers 120_2.
In the following description, of the plural semiconductor layers 120_1 in the memory hole region RMH, the semiconductor layer 120_1 closest to one end of the memory hole region RMH in the X direction and the semiconductor layer 120_1 closest to the other end of the memory hole region RMH in the X direction will be each referred to as semiconductor layer 120_11. The semiconductor layer 120_1 second closest to the one end of the memory hole region RMH in the X direction and the semiconductor layer 120_1 second closest to the other end of the memory hole region RMH in the X direction will be each referred to as semiconductor layer 120_12. Similarly, the semiconductor layer 120_1 nth (n represents an integer of 1 or larger) closest to the one end of the memory hole region RMH in the X direction and the semiconductor layer 120_1 nth closest to the other end of the memory hole region RMH in the X direction will be each referred to as semiconductor layer 120_1n. A width of the semiconductor layer 120_1n will be referred to as width X1n. The width X1n is larger than a width X1(n+1).
Suppose, for example, that n is 1, and that n is 2. The semiconductor layer 120_11 and the semiconductor layer 120_12 respectively have a width X11 and a width X12 in the X direction. The width X11 is larger than the width X12.
A distance between the semiconductor layer 120_11 and the insulating layer STH_O in the X direction will be referred to as distance D_SO_11, and a distance between the semiconductor layer 120_11 and the insulating layer STH_E in the X direction will be referred to as distance D_SE_11. A distance between the semiconductor layer 120_12 and the insulating layer STH_O in the X direction will be referred to as distance D_SO_12, and a distance between the semiconductor layer 120_12 and the insulating layer STH_E in the X direction will be referred to as distance D_SE_12. In this case, the smaller one of the distance D_SO_11 and the distance D_SE_11 is smaller than the smaller one of the distance D_SO_12 and the distance D_SE_12.
In the following description, of the plural semiconductor layers 120_2 in the memory hole region RMH, the semiconductor layer 120_2 mth (m is an integer of 1 or larger) closest to the one end of the memory hole region RMH in the X direction and the semiconductor layer 120_2 mth closest to the other end of the memory hole region RMH in the X direction will be each referred to as semiconductor layer 120_2m. A width of the semiconductor layer 120_2m will be referred to as width X2m. The width X2m is larger than a width X2(m+1).
Suppose, for example, that m is 1, and that m is 2. The semiconductor layer 120_21 and the semiconductor layer 120_22 respectively have a width X21 and a width X22 in the X direction. The width X21 is larger than the width X22.
A distance between the semiconductor layer 120_21 and the insulating layer STH_O in the X direction will be referred to as distance D_SO_21, and a distance between the semiconductor layer 120_21 and the insulating layer STH_E in the X direction will be referred to as distance D_SE_21. A distance between the semiconductor layer 120_22 and the insulating layer STH_O in the X direction will be referred to as distance D_SO_22, and a distance between the semiconductor layer 120_22 and the insulating layer STH_E in the X direction will be referred to as distance D_SE_22. In this case, the smaller one of the distance D_SO_21 and the distance D_SE_21 is smaller than the smaller one of the distance D_SO_22 and the distance D_SE_22.
It is noted that in the above-described configuration, the plural semiconductor layers 120_1 may be individually next to the plural conductive layers 110_a1 and the plural conductive layers 110_b2 that are disposed in the Z direction. The plural semiconductor layers 120_2 may be individually next to the plural conductive layers 110_b2 and the plural conductive layers 110_a3 that are disposed in the Z direction.
Widths of Charge Storage Layers 132
As illustrated in
Manufacturing Method
Next, referring to
In the manufacturing method, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Insulating layers 174 of silicon oxide (SiO2), for example, are deposited on bottom surfaces and side surfaces of the openings AHa. Semiconductor layers 175 of amorphous silicon (Si), for example, to fill up the openings AHa are formed on upper surfaces of the insulating layers 174. The insulating layers 174 and the semiconductor layers 175 are formed by a method such as CVD. Upper portions of the insulating layers 174 and the semiconductor layers 175 are removed to positions flush with the upper surface of the insulating layer 103. Removal of the insulating layers 174 and the semiconductor layers 175 is performed by RIE, for example.
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Next, as illustrated in
Thereafter, silicon oxide (SiO2), for example, is deposited in the openings STHa to form the insulating layers STH, and components such as the bit line contacts BLC and the bit lines BL are formed to manufacture the semiconductor storage device according to the first embodiment.
Wet Etching of Sacrifice Layers 110A
The step of wet etching of the sacrifice layers 110A described with reference to
Description will be made on an example where the sacrifice layers 110A to be etched are made of silicon nitride (SiN), for example, and layers not to be etched, such as the block insulating layers 133 and the insulating layers 150, are made of silicon oxide (SiO2), for example. In this kind of wet etching step, such an appropriate liquid chemical is selected that an etching rate is high with respect to silicon nitride (SiN) to be etched, and that an etching rate is low with respect to silicon oxide (SiO2) not to be etched. It is noted that for the liquid chemical for etching, phosphoric acid (H3PO4), for example, may be used, and other liquid chemicals may be selected as suited.
In such an etching process, the etching progresses relatively quickly to the vicinity of the memory cells MC close to the openings STHa. Consequently, the block insulating layers 133 of the memory cells MC close to the openings STHa are exposed to the liquid chemical for a long time. Meanwhile, the etching progresses relatively slowly to the vicinity of the memory cells MC far from the openings STHa. Consequently, the block insulating layers 133 of the memory cells MC far from the openings STHa are exposed to the liquid chemical only for a relatively short time.
Shapes of the memory cells MC after the above-described step will be described with reference to
In the memory cell MC relatively close to the insulating layer STH (see
Effects of the First Embodiment
In accordance with an increased integration of the semiconductor storage device, density of the arrangement of the memory cells MC in the X direction and the Y direction is being enhanced. As the density is enhanced, more memory cells MC are disposed on an X-Y plane. For this purpose, desirably, there are provided less ladder regions RLD including the openings STHa to remove the sacrifice layers 110A described with reference to
When the distances between the insulating layers STH adjacent in the X direction are long, there is a large difference between the film thickness T11 and the film thickness T12 of the insulating layers 136 in the memory cell MC close to the insulating layer STH and the memory cell MC far from the insulating layer STH in some cases as described with reference to
Here, an influence of such a film thickness difference on write operation properties will be described. At the time of write operation, a predetermined write voltage is applied between the conductive layers 110 and the semiconductor layers 120, and a charge in the semiconductor layers 120 is stored in the charge storage layers 132 so as to adjust a threshold voltage of the memory cells MC. In the memory cell MC with the thin insulating layer 136 (see
In view of this, according to the first embodiment, as described with reference to
Next, description will be made on the phenomenon that the charge is more likely to be stored as the widths of the semiconductor layers 120 in the X direction are smaller. In an X-Y cross section (see
Next, consideration will be given to a ratio of a capacitance between the charge storage layer 132 and the conductive layer 110 to a capacitance between the charge storage layer 132 and the semiconductor layer 120 in this case. As the width of the semiconductor layer 120 in the X direction is smaller, the ratio of the area where the charge storage layer 132 is next to the conductive layer 110 increases so that the above-described ratio of the capacitance accordingly increases. In this manner, as the capacitance ratio on the conductive layer 110 side where the voltage is applied is higher, the charge is more likely to be stored in the charge storage layer 132.
Therefore, the widths of the semiconductor layers 120 in the X direction are decreased in the memory cells MC farther from the insulating layers STH so as to cancel a consequence when the thickness of the block insulating layers 133 increases in the memory cells MC farther from the insulating layers STH and makes the charge less likely to be stored. Thus, properties of the memory cells MC in the X-Y cross section can be made uniform to reduce an operational irregularity, thereby providing the semiconductor storage device capable of highly accurate write operation.
Modification of the First EmbodimentOthers
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosure. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosure.
Claims
1. A semiconductor storage device comprising:
- a first conductive layer extending in a first direction;
- a second conductive layer extending in the first direction and disposed apart from the first conductive layer in a second direction intersecting the first direction;
- a third conductive layer extending in the first direction and disposed apart from the first conductive layer and the second conductive layer in the second direction;
- a plurality of first semiconductor layers interposed between the first conductive layer and the second conductive layer, each of the plurality of first semiconductor layers including regions adjacent the first conductive layer and the second conductive layer, respectively;
- a plurality of first memory cells interposed between the first conductive layer and the plurality of first semiconductor layers;
- a plurality of second memory cells interposed between the second conductive layer and the plurality of first semiconductor layers;
- a plurality of second semiconductor layers interposed between the second conductive layer and the third conductive layer, each of the plurality of second semiconductor layers including regions adjacent the second conductive layer and the third conductive layer, respectively;
- a plurality of third memory cells interposed between the second conductive layer and the plurality of second semiconductor layers;
- a plurality of fourth memory cells interposed between the third conductive layer and the plurality of second semiconductor layers;
- a first insulating layer interposed between the first conductive layer and the second conductive layer, the first insulating layer being wider than the plurality of first semiconductor layers and the plurality of second semiconductor layers in the second direction; and
- a second insulating layer interposed between the second conductive layer and the third conductive layer, the second insulating layer being wider than the first semiconductor layers and the second semiconductor layers in the second direction,
- wherein a third semiconductor layer and a fourth semiconductor layer from among the plurality of first semiconductor layers are provided as follows: the third semiconductor layer has a first width in the first direction; the third semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a first distance; the third semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with a second distance; the fourth semiconductor layer has a second width in the first direction; the fourth semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a third distance; and the fourth semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with a fourth distance,
- wherein a shorter one of the first distance and the second distance is shorter than a shorter one of the third distance and the fourth distance, and the first width is larger than the second width.
2. The semiconductor storage device according to claim 1, wherein a fifth one and a sixth one of the plurality of second semiconductor layers are provided as follows: the fifth semiconductor layer has a third width in the first direction; the fifth semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a fifth distance; the fifth semiconductor layer and the second insulating layer has a sixth distance in the first direction; the sixth semiconductor layer has a fourth width in the first direction; the sixth semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a seventh distance; and the sixth semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with an eighth distance, and
- wherein a shorter one of the fifth distance and the sixth distance is shorter than a shorter one of the seventh distance and the eighth distance, and the third width is larger than the fourth width.
3. The semiconductor storage device according to claim 1, comprising:
- a plurality of the first conductive layers disposed in a third direction intersecting the first direction and the second direction;
- a plurality of the second conductive layers disposed in the third direction; and
- a plurality of the third conductive layers disposed in the third direction.
4. The semiconductor storage device according to claim 3, wherein the first insulating layer and the second insulating layer extend in the third direction and are interposed between the plurality of first conductive layers and the plurality of second conductive layers, or between the plurality of third conductive layers and the plurality of second conductive layers.
5. The semiconductor storage device according to claim 1, further comprising:
- a plurality of first charge storage layers interposed between the first conductive layer and the plurality of first semiconductor layers; and
- a plurality of second charge storage layers interposed between the second conductive layer and the plurality of first semiconductor layers.
6. The semiconductor storage device according to claim 1, wherein the plurality of first semiconductor layers and the plurality of second semiconductor layers each extend in a third direction intersecting the first direction and the second direction.
7. The semiconductor storage device according to claim 1, further comprising a third semiconductor layer with an N-type impurity disposed on an upper end of each of the first and second semiconductor layers.
8. The semiconductor storage device according to claim 1, further comprising a gate insulating layer between each of the plurality of first semiconductor layers and the first conductive layer, between each of the plurality of first semiconductor layers and the second conductive layer, between each of the plurality of second semiconductor layers and the second conductive layer, between each of the plurality of second semiconductor layers and the third conductive layer.
9. The semiconductor storage device according to claim 8, wherein the gate insulating layer includes a tunnel insulating layer, a charge storage layer, and a block insulating layer.
10. A semiconductor storage device comprising:
- a plurality of first semiconductor layers disposed with respect to each other in a first direction, the plurality of first semiconductor layers each including regions disposed adjacent a first conductive layer and a second conductive layer, respectively;
- a plurality of second semiconductor layers disposed with respect to each other in the first direction, each of the plurality of second semiconductor layers including a region disposed adjacent the second conductive layer and a third conductive layer, respectively, wherein the first to third conductive layers, each extending along the first direction, are disposed with respect to each other in a second direction perpendicular to the first direction;
- a first insulating layer interposed between the first conductive layer and the second conductive layer, the first insulating layer being wider than the plurality of first semiconductor layers and the plurality of second semiconductor layers in the second direction;
- a second insulating layer interposed between the second conductive layer and the third conductive layer, the second insulating layer being wider than the first semiconductor layer and the second semiconductor layer in the second direction,
- wherein a third one and a fourth one of the plurality of first semiconductor layers are provided as follows: the third semiconductor layer has a first width in the first direction; the third semiconductor layer and the first insulating layer are disposed apart from each other in the first direction with a first distance; the third semiconductor layer and the second insulating layer are disposed apart from each other in the first direction with a second distance; the fourth semiconductor layer has a second width in the first direction; the fourth semiconductor layer and the first insulating layer are separated apart from each other in the first direction with a third distance; and the fourth semiconductor layer and the second insulating layer are separated apart from each other in the first direction with a fourth distance, and
- wherein a shorter one of the first distance and the second distance is shorter than a shorter one of the third distance and the fourth distance, and the first width is larger than the second width.
11. The semiconductor storage device according to claim 10, wherein a plurality of first memory cells are interposed between the first conductive layer and the plurality of first semiconductor layers, and a plurality of second memory cells interposed between the second conductive layer and the plurality of first semiconductor layers.
12. The semiconductor storage device according to claim 10, wherein a plurality of third memory cells are interposed between the second conductive layer and the plurality of second semiconductor layers, and a plurality of fourth memory cells interposed between the third conductive layer and the plurality of second semiconductor layers.
13. The semiconductor storage device according to claim 10, wherein the first insulating layer and the second insulating layer each extend in a third direction perpendicular to the first and second directions.
14. The semiconductor storage device according to claim 10, wherein the plurality of first semiconductor layers and the plurality of second semiconductor layers each extend in a third direction perpendicular to the first and second directions.
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Type: Grant
Filed: Aug 30, 2021
Date of Patent: Apr 16, 2024
Patent Publication Number: 20220310646
Assignee: KIOXIA CORPORATION (Tokyo)
Inventor: Yusuke Arayashiki (Mie)
Primary Examiner: Earl N Taylor
Application Number: 17/460,944